Coating compositions suitable for use with an overcoated photoresist

ABSTRACT

In one aspect, organic coating compositions, particularly antireflective coating compositions, are provided that comprise that comprise a diene/dienophile reaction product. In another aspect, organic coating compositions, particularly antireflective coating compositions, are provided that comprise a component comprising a hydroxyl-naphthoic group, such as a 6-hydroxy-2-naphthoic group Preferred compositions of the invention are useful to reduce reflection of exposing radiation from a substrate back into an overcoated photoresist layer and/or function as a planarizing, conformal or via-fill layer.

This application claims the benefit of priority under 35 U.S.C. §119(e)to U.S. Provisional Application No. 61/186,802, filed Jun. 12, 2009, thecontents of which application are incorporated herein by reference.

The present invention relates to compositions (including antireflectivecoating compositions or “ARCs”) that can reduce reflection of exposingradiation from a substrate back into an overcoated photoresist layerand/or function as a planarizing, conformal or via-fill layer. Moreparticularly, in one aspect, the invention relates to organic coatingcompositions, particularly antireflective coating compositions, thatcomprise a diene/dienophile reaction product. In another aspect, theinvention relates to relates to organic coating compositions,particularly antireflective coating compositions, that comprise acomponent comprising a hydroxyl-naphthoic group, such as a6-hydroxy-2-naphthoic group.

Photoresists are photosensitive films used for the transfer of images toa substrate. A coating layer of a photoresist is formed on a substrateand the photoresist layer is then exposed through a photomask to asource of activating radiation. Following exposure, the photoresist isdeveloped to provide a relief image that permits selective processing ofa substrate.

A major use of photoresists is in semiconductor manufacture where anobject is to convert a highly polished semiconductor slice, such assilicon or gallium arsenide, into a complex matrix of electronconducting paths, preferably of micron or submicron geometry, thatperform circuit functions. Proper photoresist processing is a key toattaining this object. While there is a strong interdependency among thevarious photoresist processing steps, exposure is believed to be one ofthe most important steps in attaining high resolution photoresistimages.

Reflection of activating radiation used to expose a photoresist oftenposes limits on resolution of the image patterned in the photoresistlayer. Reflection of radiation from the substrate/photoresist interfacecan produce spatial variations in the radiation intensity in thephotoresist, resulting in non-uniform photoresist linewidth upondevelopment. Radiation also can scatter from the substrate/photoresistinterface into regions of the photoresist where exposure is notintended, again resulting in linewidth variations. The amount ofscattering and reflection will typically vary from region to region,resulting in further linewidth non-uniformity. Variations in substratetopography also can give rise to resolution-limiting problems.

One approach used to reduce the problem of reflected radiation has beenthe use of a radiation absorbing layer interposed between the substratesurface and the photoresist coating layer.

While current organic antireflective coating compositions are highlyeffective for many applications, it is also frequently desired to haveparticular antireflective compositions to meet specific processingrequirements. For instance, it may be desired to remove anantireflective layer that has been bared of overcoated photoresist (e.g.with a positive resist, exposed resist areas removed by alkaline aqueousdeveloper) by means other than a plasma etchant. See U.S. Pat. No.6,844,131 and U.S. Patent Publication US20050181299. Such approachesoffer the potential of avoiding additional processing steps and pitfallsassociated with plasma etchant removal of a bottom antireflectivecoating layer.

It would be desirable to have new compositions that could be used asunderlying antireflective coating layer in the manufacture ofmicroelectronic wafers. It would be particularly desirable to have newcompositions that could be used as underlying antireflective coatinglayer and could be removed with an aqueous photoresist developer.

We have now discovered new coating compositions that are particularlyuseful as underlying antireflective coating layers for an overcoatedphotoresist layer.

More particularly, in a first aspect, the invention providescompositions that comprise a component (sometimes referred to herein asa “reaction product component”) that is a reaction product of a dieneand a dienophile. Preferred dienes and dienophile both have unsaturatedgroups and preferably can combine to form a cyclic adduct in which thereis a net reduction of the bond multiplicity. Preferred dienes areelectron-rich include carbocyclic or heteroaromatic groups, includingmultiple ring carbocyclic or heteroaromatic groups, particularly fusedring groups such as anthracene or pentacene groups. Preferreddienophiles include groups that comprise olefin moieties that haveproximate (e.g. within 1, 2, or 3 atoms) electron-withdrawingsubstituent(s) e.g. preferred dienophiles include groups that compriseone or more α,β-unsaturated groups. Specifically preferred dienophilesinclude imide-containing groups particularly maleimdes, anhydrides suchas maleic anhydride, and other groups such as dimethylacetylenedicarboxylate.

In preferred aspect, the invention provides compositions that comprise areaction product component that is a Diels Alder reaction product of adiene and a dienophile as discussed above. The term “Diels Alderreaction” is used herein in accordance with its well-recognized meaning,i.e. a (4+2) cycloaddition, e.g. as refereed to under the definition of“cycloaddition” in Compendium of Chemical Technology, IUPACRecommendations, 2” edition (1997 Blackwell Science). Preferred DielsAlder reaction products include a reaction product of (i) animide-containing compound e.g. maleimide or other dienophiles e.g.anhydrides such as maleic anhydride, and other groups such asdimethylacetylene dicarboxylate and (ii) a polycyclic aromatic group.Particularly preferred Diels Alder reaction products include a reactionproduct of (1) an imide-containing compound e.g. maleimide or otherdienophiles e.g. anhydrides such as maleic anhydride, and other groupssuch as dimethylacetylene dicarboxylate and (2) an anthracene orpentacene group.

Generally preferred reaction product components of an underlying coatingcomposition of the invention are resins, including homopolymers as wellas mixed polymers such as copolymers (two distinct repeat units),terpolymers (three distinct repeat units), tetrapolymers (four distinctrepeat units), pentapolyrners (five distinct repeat units) and otherhigher order polymers.

In certain aspects, particularly preferred reaction products componentsare resins that comprise at least three or four distinct functionalgroups that can impart the following properties (1) dissolution rateinhibition; (2) strip resistance (e.g.); (3) desired aqueous alkalinedeveloper solubility (e.g. a photoacid-labile group such as aphotoacid-labile ester (e.g. —C(═O)OC(CH₃)₃) or an acetal moiety); and(4) a chromophore group to absorb undesired reflections of photoresistexposure radiation (e.g. a carbocyclic aryl group such as optionallysubstituted phenyl, naphthyl or anthraceny1).

Significantly, preferred processed coating compositions of the inventionmay be removed to expose an underlying surface with an aqueous alkalinedeveloper used for development of an overcoated photoresist layer. Thisoffers a number of notable advantages, including reducing the additionalprocessing step and costs required with use of a plasma etchant toremove the underlying coating layer.

In another aspect, organic coating compositions are provided,particularly antireflective coating compositions, that comprise acomponent comprising a hydroxyl-naphthoic group (e.g. C₉H₆(OH)(COO—),such as a 6-hydroxy-2-naphthoic group. In preferred aspects, as referredto herein, a hydroxyl-naphthoic moiety or other similar term refers to anaphthyl moiety that has both hydroxyl (—OH) and carboxy (—C(═OO—) ringsubstituents, and may have additional non-hydrogen ring substituentssuch as e.g. halo (e.g. F, Cl, Br, I), alkoxy such as optionallysubstituted C₁₋₁₂alkoxy, alkyl such as optionally substituted C₁₋₁₂alkoxy, and the like.

In a preferred embodiment, multiple aspects of the invention are used incombination. More particularly, a preferred embodiments includes organiccoating compositions are provided, particularly antireflective coatingcompositions, that comprise a component that comprises (1) ahydroxyl-naphthoic group, such as a 6-hydroxy-2-naphthoic group and (2)a reaction product of a diene and a dienophile as disclosed herein. In aparticular preferred system, the underlying coating composition maycomprise a resin that comprises multiple repeat units that comprise (1)a hydroxyl-naphthoic group, such as a 6-hydroxy-2-naphthoic group and(2) a reaction product of a diene and a dienophile as disclosed herein.

It has been found that hydroxyl-naphthoic groups, such as a6-hydroxy-2-naphthoic group, can be effective chromophores of undesiredreflections of exposure of an overcoated photoresist layer.

Coating compositions of the invention also may optionally contain one ormore other materials in addition to the reaction component and/or acomponent that comprises a hydroxyl-naphthoic group. For example, acoating composition of the invention may contain an additional componentthat comprises chromophore groups that can absorb undesired radiationused to expose the overcoated resist layer from reflecting back into theresist layer. Such chromophore groups may be present a variety ofcomposition components including the reaction component itself or anadditional component may comprise chromophore groups such as an addedresin which may have chromophore groups as backbone members or aspendant groups, and/or an added small molecule (e.g. MW less than about1000 or 500) that contains one or more chromophore moieties.

Generally preferred chromophores for inclusion in coating composition ofthe invention particularly those used for antireflective applicationsinclude both single ring and multiple ring aromatic groups such asoptionally substituted phenyl, optionally substituted naphthyl,optionally substituted anthracenyl, optionally substitutedphenanthracenyl, optionally substituted quinolinyl, and the like.Particularly preferred chromophores may vary with the radiation employedto expose an overcoated resist layer. More specifically, for exposure ofan overcoated resist at 248 nm, optionally substituted anthracene andoptionally substituted naphthyl are preferred chromophores of theantireflective composition. For exposure of an overcoated resist at 193nm, optionally substituted phenyl and optionally substituted naphthylare particularly preferred chromophores.

Coating compositions of the invention also may optionally comprise anacid or acid generator compound (e.g. photoacid generator and/or thermalacid generator) to facilitate reaction of composition component(s)during lithographic thermal processing of an applied composition coatinglayer. A photoacid generator compound (i.e. a compound that can generateacid upon exposure to activating radiation such as 193 nm) and/orothermal acid generator compound (i.e. a compound that can generate acidupon thermal treatment) is generally suitable.

Photoacid generator compound(s) included in an underlying coatingcomposition can generate acid upon treatment with radiation used toexpose an overcoated photoresist layer. By such use of photoacidgenerator compound(s), acid is not liberated from the photoacidgenerator compound(s) prior to application of a photoresist layer overthe underlying coating composition. Exposure of the applied resist layerto patterned activating radiation liberates acid from the coatingcomposition photoacid generator compound(s) and can enhance resolutionof the resist image patterned over the coating composition layer bycompensating for photoacid at the resist/coating composition that maydiffuse from the resist into the coating composition as well asfacilitate desired selective development of the underlying coatingcomposition during treatment with an aqueous alkaline developer.

A coating composition may be provided by an admixture of a reactioncomponent and/or a component that comprises a hydroxyl-naphthoic group(which may include a single material e.g. a resin that comprisestogether with one or more optional components as discussed above in asolvent component. The solvent component suitably may be one or moreorganic solvents such as one or more alcohol solvents e.g. ethyllactate, propylene glycol methyl ether (1-methoxy-2-propanol),methyl-2-hydroxyisobutyrate, and the like, and/or one more non-hydroxysolvents such as ethyl ethoxy propionate, propylene glycol methyl etheracetate (1-methoxy-2-propanol acetate), and the like.

The coating composition is then applied such as by spin-coating (i.e. aspin-on composition) to a substrate such as a microelectronicsemiconductor wafer. The solvent carrier may be removed by heating, e.g.170° C. to 250° C. on a vacuum hotplate.

A variety of photoresists may be used in combination (i.e. overcoated)with a coating composition of the invention. Preferred photoresists foruse with the antireflective compositions of the invention arechemically-amplified resists, especially positive-acting photoresiststhat contain one or more photoacid generator compounds and a resincomponent that contains units that undergo a deblocking or cleavagereaction in the presence of photogenerated acid, such asphotoacid-labile ester, acetal, ketal or ether units. Preferredphotoresists for use with a coating composition of the invention may beimaged with relatively short-wavelength radiation, e.g. radiation havinga wavelength of less than 300 nm or less than 260 nm such as about 248nm, or radiation having a wavelength of less than about 200 nm, such as193 nm or 157 nm. Other useful exposure energies include EUV, e-beam,IPL, and x-ray exposures.

The invention further provides methods for forming a photoresist reliefimage and novel articles of manufacture comprising substrates (such as amicroelectronic wafer substrate) coated with an antireflectivecomposition of the invention alone or in combination with a photoresistcomposition. As discussed above, a processed underlying coatingcomposition layer may be removed with the same aqueous, alkalinedeveloper solution used to develop an overcoated photoresist layer, i.e.both the exposed photoresist layer and underlying cured coatingcomposition can be removed in a single step with an aqueous alkalinedeveloper in those regions defined by the photomask during exposure.

More particularly, preferred methods of the invention may include:

1. Applying a coating layer of a composition that comprises one or morereaction components and/or components that comprises ahydroxyl-naphthoic group as discussed above. The composition coatinglayer may be applied over a variety of substrates including amicroelectronic wafer;

2. Preferably thermally treating the applied composition coating layer.The thermal treatment can remove casting solvent of the coatingcomposition and render that composition layer substantially insoluble inphotoresist casting solvents such as ethyl lactate, propylene glycolmethyl ether acetate, 2-heptanone, and the like;

3. Applying a photoresist composition coating layer over the thermallybaked underlying composition coating layer. The applied photoresistlayer is exposed to activating radiation such as radiation having awavelength of below 300 nm such as 248 nm, or below 200 run such as 193nm, typically through a photomask to form a patterned image in theresist layer. The exposed photoresist may be thermally treated as neededto enhance or form the latent image;

4. The exposed photoresist layer is then treated with a developersolution, such as an aqueous, alkaline developer solution. The developersolution can remove the image defined in the resist layer as well asmatching region of the underlying coating composition layer, i.e. wherea relief image is defined through both the photoresist layer and theunderlying coating composition layer.

In preferred aspects an underlying coating composition of the inventionis used in combination with a positive-acting photoresist, e.g. as maybe imaged at sub-300 nm and sub-200 nm wavelengths such as 248 nm or 193nm. Chemically-amplified positive resists are preferred, which contain acomponent that has moieties that will undergo a deblocking or cleavagereaction in the presence of photogenerated acid, such asphotoacid-labile esters or acetals. Preferred positive-actingphotoresists for sub-300 nm imaging such as 248 nm comprise a polymerthat comprises phenolic units and acid-labile esters and/or acetalmoieties and a photoacid generator compound. Preferred positive-actingphotoresists for use at sub-200 nm imaging such as 193 nm imaging aresubstantially free of aromatic groups, particularly resins that containphenyl or other aromatic substitution.

In another aspect, the invention also includes methods for producing acoating composition of the invention, and methods for forming aphotoresist relief image and methods for manufacturing an electronicdevice such as a processed microelectronic wafer.

In yet another aspect of the invention, compounds (such as a resin) areprovided which comprise one or more groups of the following formulae:

where in the above formulae each R is independently hydrogen or anon-hydrogen such as e.g. ═H, C₁₋₁₈alkyl including methyl, aryl(including carbocyclic aryl such as phenyl, naphthyl), and C₁₋₁₈alkoxy.

Preferred compounds of the above formulae include resins, where one ormore repeat units may comprise one or more of the above groups. Forinstance, the following preferred acrylate compounds may be polymerizedwith other reactive monomers to provide a resin comprising polymerizedunits:

where in the above formulae each R is independently hydrogen or anon-hydrogen such as e.g. ═H, C₁₋₁₈alkyl including methyl, aryl(including carbocyclic aryl such as phenyl, naphthyl), and C₁₋₁₈alkoxy;and R′ is hydrogen or C₁ _(—) ₆alkyl such as methyl.

Other aspects of the invention are disclosed infra.

As discussed above, we now provide new organic coating compositions thatare particularly useful with an overcoated photoresist layer. Preferredcoating compositions of the invention may be applied by spin-coating(spin-on compositions) and formulated as a solvent composition. Thecoating compositions of the invention are especially useful asantireflective compositions for an overcoated photoresist.

Underlying Coating Compositions

As discussed above, in a first aspect, underlying coating compositionscomprise reaction product component that is a reaction product of adiene and a dienophile. In another aspect, underlying coatingcompositions comprise a reaction product component that that is a DielsAlder reaction product. Suitably, reaction product components areresins, including both homopolymers as well as higher order polymerssuch as copolymers, terpolymers, tetrapolymers and pentrapolymers.

In another aspect, organic coating compositions are provided,particularly antireflective coating compositions, that comprise acomponent comprising a hydroxyl-naphthoic group, such as a6-hydroxy-2-naphthoic group.

Preferred hydroxyl-naphthoic groups include the following structures:

Preferred resins that comprise hydroxyl-naphthoic groups for use in anunderlying coating composition include resins that comprise thefollowing structure (pentapolymer):

Preferred syntheses of monomers and components such as resins thatcomprise a hydroxyl-naphthoic group, such as a 6-hydroxy-2-naphthoicgroup are set forth in the examples which follow.

Reaction product components can be synthesized by a variety of methods.For instance, a monomer can be preferred that is a Diels Alder reactionproduct of two materials. That monomer then can be reacted with othermonomers to provide a resin component of an underlying coatingcomposition of the invention. Diels Alder and other cycloadditionreactions are known.

Alternatively, a formed resin containing either or both a diene (e.g.anthracene or pentacene) and a dienophile (e.g. a substrate comprisingan olefin with one or more electron-withdrawing substituents, such asmaleimide, maleic anhydride or dimethylacetylene dicarboxylate) canundergo a cycloaddition reaction to provide a reaction product componentof an underlying coating composition of the invention. See, forinstance, Examples 4-6 which follow for exemplary syntheses of areaction product component from a pre-formed polymer.

More particularly, the following Scheme 1 depicts an exemplary monomermodified via Diels Alder reaction that can be polymerized to provide aresin reaction product component of an underlying coating composition ofthe invention.

Scheme 1 above depicts the cycloaddition (particularly, Diels-Alder)reaction of anthracenemethylmethacrylate monomer, 1, with aN-substituted maleimide to afford a modified methacrylic monomer, 2,with a pendant maleimide functionality. Monomer 2 can provide strongabsorbance at 193 nm due to the two benzo-fused aromatic substituents.Additionally, the pendant maleimide adduct can impact base dissolutioncharacteristics and solvent strip resistance to an otherwise solventsoluble and base insoluble monomer 1.

Under the reaction conditions shown in Scheme 1 (refluxing dioxane, 12hrs), it has been found that the depicted cycloaddition reactionproceeds readily. See also the examples which follow for exemplarypreferred reaction conditions.

The following Scheme 2 depicts an exemplary monomer modified via DielsAlder reaction that can be polymerized to provide a resin reactionproduct component of an underlying coating composition of the invention.

Scheme 2 above depicts the cycloaddition (particularly, Diels-Alder)reaction of pentacenenthracenemethylmethacrylate monomer with aN-substituted maleimide to afford a modified methacrylic monomer with apendant maleimide functionality. Monomer 2 can provide strong absorbanceat 193 nm due to the two benzo-fused aromatic substituents.Additionally, the pendant maleimide adduct can impact base dissolutioncharacteristics and solvent strip resistance to an otherwise solventsoluble and base insoluble pentacenenthracenemethylmethacrylate monomer.

As discussed above, preferably regions of a layer of an underlyingcoating composition can be selectively removed with an aqueous alkalinedeveloper composition (e.g. 0.26N tetramethyl ammonium hydroxide aqueousdeveloper solution). Preferred reaction product components are polymerswith multiple, distinct functional groups.

Preferred underlying coating compositions of the invention do notundergo significant crosslinking (molecular weight increases ofcomposition component(s)) upon thermal treatment such as 180° C. or 240°C. for 1 to 5 minutes. See Example 15 which follows for a protocol forassessing whether a coating layer does not undergo substantialcrosslinking.

Preferred reaction product components of an underlying coatingcomposition comprise one or more photoacid-labile group which canundergo a cleavage or deprotection reaction to provide functionalgroup(s) which promote aqueous alkaline-developer solubility, such ascarboxy, fluorinated alcohol, phenols, imides, sulfonamides, and othersuch moieties. Upon image-wise exposure and post-exposure bake of anovercoated photoresist layer, the photoacid-labile groups of thereaction component(s) and/or component(s) that comprises ahydroxyl-naphthoic group of the underlying coating composition can reactand liberate functional group(s) which promote aqueousalkaline-developer solubility.

Preferably, a reaction product component of an underlying coatingcomposition contains other functional groups in addition to acid labilegroups, such as chromophore component in carrier solvent(s) of anovercoated photoresist layer); dissolution ratepromoters (do not containphotoacid-labile groups but nevertheless can promote dissolution rate inaqueous alkaline developer; acid-labile groups); and the like.

More particularly, preferred functional groups of a reaction productcomponent include the following:

1. Chromophore groups: An organic functional group with sufficientabsorbance at 248 nm (KrF exposure) or 193 nm (ArF exposure) to providefor reflection control in antireflective applications. Varioussubstituted anthracenes, naphthalenes, and phenyl groups are examples ofpreferred chromophores. Such chromophores may be incorporated into apolymer using the following monomers: anthracene methyl methacrylate(ANTMA), hydroxystyrene monomer (PHS), acetoxy-styrene monomer (4AS),hydroxyvinylnaphthalene monomer (HVN), and 2-Methyl-acrylic acid6-hydroxy-naphthalen-2-ylmethyl ester.

2. Solvent strip resistance groups. An organic functional group that, asa component of a polymer, decreases the rate of dissolution of thepolymer in the various selected organic solvents that are commonlyemployed in KrF and ArF-type resist formulations. These include PGMEA,ethyl lactate, and hydroxy isobutyric acid methyl ester. Solvent stripresistance groups can permit the application of an over-coatedphotoresist layer to the underlayer without intermixing. Varioussubstituted amides, lactones, carboxylic acids, carboxylic acid estersand other hydrolysable groups are examples of functional groups that canprovide solvent strip resistance to a polymer-based underlayercomposition. Such solvent strip resistance promoters may be incorporatedinto a polymer using the following exemplary monomers: maleimide,norbornyl lactone acrylate monomer (NLA), norbornyl lactone methacrylatemonomer (NLM), and anthracenemethylmethacrylate-maleimide cycloadduct(ANT-MI).

3. Dissolution rate promoter groups. An organic functional group that,as a component of a polymer, promotes (increases) the rate ofdissolution of the polymer in aqueous tetramethylammonium hydroxidesolution (0.26N). Various substituted imides, amides, phenols,sulfonamides, fluorinated alcohols including hexfluoroalcohols (e.g.—C(CF₃)₂OH), groups are examples of preferred dissolution ratepromoters. Such dissolution rate promoters may be incorporated into apolymer using the following monomers: maleimide, hydroxystyrene monomer,acetoxystyrene monomer, hydroxyvinylnaphthalene monomer, norbornyllactone acrylate monomer (NLA), norbornyl lactone methacrylate monomer(NLM), and anthracenemethylmethacrylate-maleimide cycloadduct (ANT-MI).

4. Acid-labile groups. An organic functional group that, as a componentof apolymer, may undergo an acid-catalyzed deprotection reaction. Inthese applications, the acid-catalyst is provided by means of aphoto-acid generator (PAG), which provides acid in the exposed regionsduring the photolithographic processing of an over-coated photoresist.The deprotection reaction significantly increases the rate ofdissolution of the polymer in developer solutions, permitting theremoval of the photoresist and the underlying coating compositions inexposed areas with good pattern fidelity. The fast dissolution rate inaqueous developer solutions, provided by the de-protected acid labilegroups, eliminates or at least minimizes any underlying coatingcomposition residue or scumming observed in the exposed regions afterdevelopment. The acid-catalyzed de-protection reaction of tert-butylacrylate esters is a preferred example.

Suitable molecular weights of resin reaction product components ofunderlying coating compositions of the invention may vary rather widely,e.g. suitably weight average molecular weights may range from about1,000 to 50,000, more preferably about 1,500 to 10,000, 20,000 or30,000.

Exemplary reaction product components for use in the present underlyingcoating compositions are set forth in the examples which follow as wellas Schemes 1 and 2 above.

As discussed above, particularly preferred underlying coatingcompositions of the invention additionally may comprise one or morephotoacid generator compounds. Activation of the photoacid generatorcompound(s) during image-wise exposure a an overcoated photoresist layercan result in reaction of acid-labile groups of the reactioncomponent(s) of the underlying coating composition and enable subsequentone-step development of both the imaged photoresist and underlyingcoating composition layers.

A wide variety of photoacid generator compounds may be employed in anunderlying coating compositions including ionic and compounds e.g. oniumsalts (such as sulfonium and/or iodonium compounds), and non-ionicphotoacid generators such as imidosulfonates, N-sulfonyloxyimides,disulfone compounds, and nitrobenzyl-based photoacid generators, andother photoacid generators that have been used in photoresistcompositions. Specifically suitable photoacid generator compounds foruse in the present coating compositions include those identified belowfor use in photoresist compositions as well as the ionic and non-ionicphotoacid generators disclosed in U.S. Pat. Nos. 6,20,911 and 6,803,169,such as sulfonium compounds including triphenyl sulfonium salts,iodonium compounds including diphenyl iodonium compounds andimidosulfonates and other non-ionic photoacid generator compounds.

One or more photoacid generators may be employed in an underlyingcoating composition in a variety of amounts, e.g. where the one or morephotoacid generator compounds are percent in amounts of about 5 weightpercent or less based on total solids (all components except solventcarrier) of an underlying coating composition, suitably less than 4, 3,2 or even 1 weight percent of total solids of an underlying coatingcomposition. Another optional additive of underlying coatingcompositions of invention, particularly when one or more photoacidgenerator compounds are present in such composition is an added base,e.g. tetrabutylammonium hydroxide (TBAH), or tetrabutylammonium lactate,or a hindered amine such as diazabicyclo undecene or diazabicyclononene.The added base is suitably used in relatively small amounts, e.g. about0.03 to 5 percent by weight relative to the total solids of theunderlying coating composition.

Coating compositions of the invention, particularly for reflectioncontrol applications, also may contain additional dye compounds thatabsorb radiation used to expose an overcoated photoresist layer. Otheroptional additives include surface leveling agents, for example, theleveling agent available under the tradename Silwet 7604 from UnionCarbide, or the surfactant FC 171 or FC 431 available from the 3MCompany, or PF656 surfactant from Omnova.

Still further optional additives of an underlying coating compositionare one or more resins in addition to and distinct from any resins ofthe resin product component. For instance, a polyester or acrylate-basedresin that comprises desired chromophore groups (e.g. anthracene, phenylor naphthyl) may be included in a composition both to provide thechromophore function (i.e. absorption of undesired reflection ofexposure radiation) as well as film-forming properties to the appliedcomposition.

As discussed above, a coating composition of the invention is suitablyformulated as a liquid spin-on composition and contain one or moreblended solvents. Suitable solvents include e.g. a lactate such as ethyllactate or methyl lactate, an acetate such as amyl acetate, anisole, oneor more of the glycol ethers such as 2-methoxyethyl ether (diglyme),ethylene glycol monomethyl ether, and propylene glycol monomethyl ether;solvents that have both ether and hydroxy moieties such as methoxybutanol, ethoxy butanol, methoxy propanol, and ethoxy propanol; esterssuch as methyl cellosolve acetate, ethyl cellosolve acetate,methyl-2-hydroxyisobutyrate, propylene glycol monomethyl ether acetate,dipropylene glycol monomethyl ether acetate and other solvents such asdibasic esters, propylene carbonate and gamma-butyrolactone, ketonessuch as heptanone (particularly 2-heptanone) and cyclohexanone, and thelike.

To make a liquid coating composition of the invention, the component(s)of the coating composition are dissolved in a suitable solvent such as,for example, one or more of ethyl lactate, propylene glycol methyl esteracetate, and/or methyl-2-hydroxyisobutyrate. The preferred concentrationof the dry component(s) in the solvent will depend on several factorssuch as the method of application. In general, the solids content of acoating composition varies from about 0.5 to 20 weight percent of thetotal weight of the coating composition, preferably the solids contentvaries from about 1 to 10 weight of the coating composition. Of thetotal solids (all materials except solvent carrier) of an underlayingcoating composition, the reaction product component (e.g. one or moreresins) may comprises the majority of the weight of total solids of thecomposition, e.g. where 60, 70, 80, 90, 95 or more weight percent of acoating composition is comprised of the reaction product component. Seethe examples which follow for exemplary preferred amounts of materialsof underlying coating compositions of the invention.

Photoresist Compositions

A variety of photoresist compositions can be employed with coatingcompositions of the invention, including positive-actingphotoacid-generating compositions, as discussed above. Photoresists usedwith coating compositions of the invention typically comprise a resinand a photoactive component, typically a photoacid generator compound.Preferably the photoresist resin binder has functional groups thatimpart alkaline aqueous developability to the imaged resist composition.

As discussed above, particularly preferred photoresists for use withcoating compositions of the invention include chemically-amplifiedresists, including positive acting chemically-amplified resistcompositions, where the photoactivated acid in the resist layer inducesa deprotection-type reaction of one or more composition components tothereby provide solubility differentials between exposed and unexposedregions of the resist coating layer. A number of chemically-amplifiedresist compositions have been described, e.g., in U.S. Pat. Nos.4,968,581; 4,883,740; 4,810,613; 4,491,628 and 5,492,793, all of whichare incorporated herein by reference for their teaching of making andusing chemically amplified positive-acting resists.

Coating compositions of the invention also may be used with otherpositive resists, including those that contain resin binders thatcomprise polar functional groups such as hydroxyl or carboxyl and theresin is used in a resist composition in an amount sufficient to renderthe resist developable with an aqueous alkaline solution. Generallypreferred resist resins are phenolic resins including phenol aldehydecondensates known in the art as novolak resins, homo and copolymers oralkenyl phenols and homo and copolymers of N-hydroxyphenyl-maleimides aswell as copolymers of fluorinated alcohols including hexafluoroalcohols(e.g. —C(CF₃)₂OH—).

Preferred positive-acting photoresists for use with an underlyingcoating composition of the invention contains an imaging-effectiveamount of photoacid generator compounds and one or more resins that areselected from the group of:

1) a phenolic resin that contains acid-labile groups that can provide achemically amplified positive resist particularly suitable for imagingat 248 nm. Particularly preferred resins of this class include: i)polymers that contain polymerized units of a vinyl phenol and an alkylacrylate, where the polymerized alkyl acrylate units can undergo adeblocking reaction in the presence of photoacid. Exemplary alkylacrylates that can undergo a photoacid-induced deblocking reactioninclude e.g. t-butyl acrylate, t-butyl methacrylate, methyladamantylacrylate, methyl adamantyl methacrylate,and other non-cyclic alkyl andalicyclic acrylates that can undergo a photoacid-induced reaction, suchas polymers in U.S. Pat. Nos. 6,042,997 and 5,492,793, incorporatedherein by reference; ii) polymers that contain polymerized units of avinyl phenol, an optionally substituted vinyl phenyl (e.g. styrene) thatdoes not contain a hydroxy or carboxy ring substituent, and an alkylacrylate such as those deblocking groups described with polymers i)above, such as polymers described in U.S. Pat. No. 6,042,997,incorporated herein by reference; iii) polymers that contain repeatunits that comprise an acetal or ketal moiety that will react withphotoacid, and optionally aromatic repeat units such as phenyl orphenolic groups; such polymers have been described in U.S. Pat. Nos.5,929,176 and 6,090,526, incorporated herein by reference; (iv) polymersthat comprise t-butoxycarbonyl oxy protecting (tBoc); and (v) polymerblends wherein at least one polymer of the blend comprises acid-labilegroups;2) a resin that is substantially or completely free of phenyl or otheraromatic groups that can provide a chemically amplified positive resistparticularly suitable for imaging at sub-200 nm wavelengths such as 193nm. Particularly preferred resins of this class include: i) polymersthat contain polymerized units of a non-aromatic cyclic olefin(endocyclic double bond) such as an optionally substituted norbornene,such as polymers described in U.S. Pat. Nos. 5,843,624, and 6,048,664,incorporated herein by reference; ii) polymers that contain alkylacrylate units such as e.g. t-butyl acrylate, t-butyl methacrylate,methyladamantyl acrylate, methyl adamantyl methacrylate, and othernon-cyclic alkyl and alicyclic acrylates; such polymers have beendescribed in U.S. Pat. No. 6,057,083; European Published ApplicationsEP01008913A1 and EP00930542A1; and U.S. pending patent application Ser.No. 09/143,462, all incorporated herein by reference, and iii) polymersthat contain polymerized anhydride units, particularly polymerizedmaleic anhydride and/or itaconic anhydride units, such as disclosed inEuropean Published Application EP01008913A1 and U.S. Pat. No. 6,048,662,both incorporated herein by reference.3) a resin that contains repeat units that contain a hetero atom,particularly oxygen and/or sulfur (but other than an anhydride, i.e. theunit does not contain a keto ring atom), and preferable aresubstantially or completely free of any aromatic units. Preferably, theheteroalicyclic unit is fused to the resin backbone, and furtherpreferred is where the resin comprises a fused carbon alicyclic unitsuch as provided by polymerization of a norborene group and/or ananhydride unit such as provided by polymerization of a maleic anhydrideor itaconic anhydride. Such resins are disclosed in PCT/US01/14914 andU.S. Pat. No. 6,306,554.4) a resin that contains fluorine substitution (fluoropolymer), e.g. asmay be provided by polymerization of tetrafluoroethylene, a fluorinatedaromatic group such as fluoro-styrene compound, and the like. Examplesof such resins are disclosed e.g. in PCT/US99/21912.

Suitable photoacid generators to employ in a photoresist coated over orabove a coating composition of the invention include imidosulfonatessuch as compounds of the following formula:

wherein R is camphor, adamantane, alkyl (e.g. CI-12 alkyl) andperfluoroalkyl such as perfluoro(C_(1.12)alkyl), particularlyperfluorooctanesulfonate, perfluorononanesulfonate and the like. Aspecifically preferred PAG isN-[(perfluorooctanesulfonyl)oxy]-5-norbomene-2,3-dicarboximide.

Other known PAGS also may be employed in the resists of the invention.Particularly for 193 nm imaging, generally preferred are PAGS that donot contain aromatic groups, such as the above-mentionedimidosulfonates, in order to provide enhanced transparency.

Other suitable photoacid generators for use in present photoresistsinclude for example: onium salts, for example, triphenylsulfoniumtrifluoromethanesulfonate, (p-tert-butoxyphenyl)diphenylsulfoniumtrifluoromethanesulfonate, tris(p-tert-butoxyphenyl)sulfoniumtrifluoromethanesulfonate, triphenylsulfonium p-toluenesulfonate;nitrobenzyl derivatives, for example, 2-nitrobenzyl p-toluenesulfonate,2,6-dinitrobenzyl p-toluenesulfonate, and 2,4-dinitrobenzylp-toluenesulfonate; sulfonic acid esters, for example,1,2,3-tris(methanesulfonyloxy)benzene,1,2,3-tris(trifluoromethanesulfonyloxy)benzene, and1,2,3-tris(p-toluenesulfonyloxy)benzene; diazomethane derivatives, forexample, bis(benzenesulfonyl)diazomethane,bis(p-toluenesulfonyDdiazomethane; glyoxime derivatives, for example,bis-O-(p-toluenensulfony1)-a-dimethylglyoxime, andbis-O-(n-butanesulfony1)-a-dimethylglyoxime; sulfonic acid esterderivatives of an N-hydroxyimide compound, for example,N-hydroxysuccinimide methanesulfonic acid ester, N-hydroxysuccinimidetrifluoromethanesulfonic acid ester; and halogen-containing triazinecompounds, for example,2-(4-methoxypheny1)-4,6-bis(trichloromethyl)-1,3,5-triazine, and2-(4-methoxynaphthyl)-4,6-bis(trichloromethyl)-1,3,5-triazine. One ormore of such PAGs can be used.

Photoresists for used with an underlying coating composition of theinvention also may contain other materials.

A preferred optional additive of photoresists overcoated a coatingcomposition of the invention is an added base, particularlytetrabutylammonium hydroxide (TBAH), or tetrabutylammonium lactate,which can enhance resolution of a developed resist relief image. Forresists imaged at 193 nm, a preferred added base is a hindered aminesuch as diazabicyclo undecene or diazabicyclononene. The added base issuitably used in relatively small amounts, e.g. about 0.03 to 5 percentby weight relative to the total solids.

Other optional photoresist additives include actinic and contrast dyes,anti-striation agents, plasticizers, speed enhancers, etc. Such optionaladditives typically will be present in minor concentration in aphotoresist composition except for fillers and dyes which may be presentin relatively large concentrations such as, e.g., in amounts of fromabout 5 to 50 percent by weight of the total weight of a resist's drycomponents.

Various substituents and materials (including reaction productscomponents and reagents to form same, resins, small molecule compounds,acid generators, etc.) as being “optionally substituted” may be suitablysubstituted at one or more available positions by e.g. halogen (F, Cl,Br, I); nitro; hydroxy; amino; alkyl such as C₁₋₈ alkyl; alkenyl such asC₂₋₈ alkenyl; alkylamino such as C_(1.8) alkylamino; carbocyclic arylsuch as phenyl, naphthyl, anthracenyl, etc; and the like.

Lithographic Processing

As discussed above, in use, a coating composition of the invention isapplied as a coating layer to a substrate by any of a variety of methodssuch as spin coating. The coating composition in general is applied on asubstrate with a dried layer thickness of between about 0.02 and 0.5 pm,preferably a dried layer thickness of between about 0.03 and 100 μm. Thesubstrate is suitably any substrate used in processes involvingphotoresists. For example, the substrate can be silicon, silicon dioxideor aluminum-aluminum oxide microelectronic wafers. Gallium arsenide,silicon carbide, ceramic, quartz or copper substrates may also beemployed. Substrates for liquid crystal display or other flat paneldisplay applications are also suitably employed, for example glasssubstrates, indium tin oxide coated substrates and the like. Substratesfor optical and optical-electronic devices (e.g. waveguides) also can beemployed.

As discussed preferably the applied coating layer is treated (e.g.thermal treatment) to remove solvent carrier (but without significantmolecular weight increases of composition component(s)) before aphotoresist composition is applied over the composition layer. Thermaltreatment conditions can vary with the components of the coatingcomposition, particularly if the coating composition contains an acid oracid source such as a thermal acid generator. Suitable thermal treatmentcure conditions may range from about 140° C. to 250° C. for about 0.5 to30 minutes. Thermal conditions preferably render the coating compositioncoating layer substantially insoluble to solvent carrier of theovercoated photoresist composition to avoid any significant intermixingof the respective two coating layers.

After treatment of the coating composition layer, a photoresist isapplied over the surface of the coating composition. As with applicationof the bottom coating composition, the overcoated photoresist can beapplied by any standard means such as by spinning, dipping, meniscus orroller coating. Following application, the photoresist coating layer istypically dried by heating to remove solvent preferably until the resistlayer is tack free.

The resist layer is then imaged with activating radiation through a maskin a conventional manner. The exposure energy is sufficient toeffectively activate the photoactive component of the resist system toproduce a patterned image in the resist coating layer. Typically, theexposure energy ranges from about 3 to 300 mJ/cm² and depending in partupon the exposure tool and the particular resist and resist processingthat is employed. The exposed resist layer may be subjected to apost-exposure bake if desired to create or enhance solubilitydifferences between exposed and unexposed regions of a coating layer.For example, many chemically amplified positive-acting resists requirepost-exposure heating to induce an acid-promoted deprotection reaction.Typically post-exposure bake conditions include temperatures of about50° C. or greater, more specifically a temperature in the range of fromabout 50° C. to about 160° C.

The exposed resist coating layer is then developed, preferably with anaqueous based developer such as an alkali exemplified by tetramethylammonium hydroxide, sodium hydroxide, potassium hydroxide, sodiumcarbonate, sodium bicarbonate, sodium silicate, sodium metasilicate,aqueous ammonia or the like. In general, development is in accordancewith art recognized procedures, except that development will also resultin removal of the underlying coating composition layer in those areasunderlying resist layer regions removed by the developer. Preferably,development will be terminated (e.g. by spin-drying and/or water rinse)once development of the image transferred from the resist layer iscomplete in the underlying coating layer to avoid excessive andundesired removal of the underlying layer, e.g. removal of thecomposition coating layer in areas where the resist layer is retained.Optimal development times to avoid either underdevelopment orover-development of the underlying coating composition layer can bereadily determined empirically with any particular system of resist,underlying composition, developer composition and developmentconditions, e.g. the development can be conducted for varying timesprior to termination as discussed above, and the developed imagesevaluated such as by scanning electron micrographs (SEMs) to determinedevelopment times or time ranges where over-development or underdevelopment does not occur.

Following development, a final bake of an acid-hardening photoresist isoften employed at temperatures of from about 100° C. to about 150° C.for several minutes to further cure the developed exposed coating layerareas.

The developed substrate may then be selectively processed on thosesubstrate areas bared of photoresist and the underlying coatingcomposition layer, for example, chemically etching or plating substrateareas bared of photoresist in accordance with procedures well known inthe art. Suitable etchants include a hydrofluoric acid etching solutionand a plasma gas etch such as an oxygen plasma etch. Notably, anadditional step of plasma removal of the underlying composition layer isnot required where removal is accomplished in the same step asphotoresist layer development, as discussed above. An implant processthen can be carried out in exposed and developed areas if desired. Alldocuments mentioned herein are incorporated herein by reference in theirentirety. The following non-limiting examples are illustrative of theinvention.

EXAMPLE 1 Synthesis of ANTMI Diels-Alder Cycloadduct (ANTMI) Monomer

Into a 1.0 L, 3-necked roundbottom flask, fitted with a magneticstirbar, condenser, heating mantle, and temperature controller, wereadded maleimide (MI, 28.7 g, 296 mmol), 9-anthracene-methyl methacrylate(ANTMA, 74.2 g, 269 mmol), hydroquinone monomethylether (MEHQ, 0.5 g, 4mmol) and 267 g dimethylformamide. The mixture was heated to reflux at153° C. under nitrogen gas for 12 hours.

After cooling to room temperature, the reaction mixture was diluted with500 g of ethyl acetate. The solution was eluted through a 3-inch silicagel pad and filtered. The solution was washed with water (3×100 g) anddried over MgSO₄. The solvent was removed under reduced pressure at roomtemperature. The material was dried under vacuum for 5 hours.

72.2 g (72%) were obtained as an off-white powder. ¹H NMR (500 MHz,dioxane-d₈): δ9.30 (s, 1H), 7.42-7.25 (m, 4H), 7.22-7.11 (m, 4H), 6.05(s, 111), 5.60-5.45 (m, 3H), 4.72 (s, 1H), 3.24 (s, 2H), 1.94 (s, 3H).¹³C NMR (125 MHz, dioxane-d₈): δ177.5, 176.9, 167.3, 143.7, 142.9,140.4, 139.9, 137.5, 127.6, 127.2, 127.1, 126.0, 125.9, 124.7, 123.9,67.2, 62.8, 50.1, 48.8, 46.4, 18.5.

EXAMPLES 2-3 Syntheses of ANT-MI Containing Polymers by DirectPolymerization EXAMPLE 2 Synthesis of ANTMI Homopolymer

Into a 0.25 L, 3-necked round bottom flask, fitted with a magnetic stirbar, condenser, heating mantle, and temperature controller, were addedmaleimide/anthracenemethylmethacrylate [4+2] Diels-Alder cycloadduct(ANTMI, 10.25 g, 32.7 mmol), 2,2-azobis(2,4-dimethylvaleronitrile (Vazo®52, 0.20 g, 0.8 mmol) and 41.8 g dioxane. The reaction mixture wassparged with nitrogen gas for 15 minutes. The reaction mixture washeated to 85° C. for 12 hours.

After cooling to room temperature, the reaction mixture was diluted with50 g dioxane and precipitated into 1.5 L of methanol. The whiteprecipitate was isolated by vacuum filtration and dried in a vacuum ovenovernight at 50° C. to give Poly(maleimide/anthracenemethylmethacrylate[4+2] Diels-Alder cycloadduct) [Poly(ANTMI)]. 7.5 g (73%) were obtainedas a white powder. GPC (THF) M_(W)=26100 Da, M_(n),=5700 Da, PDI: 4.6.

EXAMPLE 3 Synthesis of ANTMI/ANTMA 80/20 Copolymer

Into a 0.25 L, 3-necked roundbottom flask, fitted with a magneticstirbar, condenser, heating mantle, and temperature controller, wereadded maleimide/anthracenemethylmethacrylate [4+2] Diels-Aldercycloadduct (ANTMI, 22.40 g, 60.0 mmol), 9-anthracene-methylmethacrylate (ANTMA, 4.11 g, 14.9 mmol),2,2-azobis(2,4-dimethylvaleronitrile (Vazo® 52, 0.40 g, 1.6 mmol) and54.3 g dioxane. The reaction mixture was sparged with nitrogen gas for15 minutes. The reaction mixture was heated to 85° C. for 12 hours.

After cooling to room temperature, the reaction mixture was diluted with60 g dioxane and precipitated into 3.0 L of methanol. The whiteprecipitate was isolated by vacuum filtration and dried in a vacuum ovenovernight at 50° C. to give Poly(maleimide/anthracenemethylmethacrylate(ANTMI)-co-9-anthracene-methyl methacrylate (ANTMA)[Poly(ANTMI)-co-(ANTMA)].

6.2 g (24%) were obtained as a white powder. GPC (THF) M_(w)=42000 Da,M_(n), 6600 Da, PDI: 6.4.

EXAMPLES 4-6 Syntheses of ANT-MI Containing Polymer via PolymerModification of Pre-Polymer EXAMPLE 4 Synthesis of ANTMA/HNMA-2/TBA50.2/33.7/16.1 Pre-Polymer

Into a 0.25 L, 3-necked round bottom flask, fitted with a magnetic stirbar, condenser, heating mantle, and temperature controller, were added42.2 g dioxane. The solvent was sparged with nitrogen gas for 15minutes. The solvent was heated to 85° C.

Into a 0.25 L glass bottle with stir bar were added 9-anthracene-methylmethacrylate (ANTMA, 34.67 g, 126 mmol),2-hydroxynaphthalene-methylmethacrylate monomer (HNMA-2, 20.47 g, 84.5mmol), t-butyl acrylate (TBA, 5.22 g, 40.7 mmol),2,2-azobis(2,4-dimethylvaleronitrile (Vazo® 52, 1.86 g, 7.5 mmol) anddioxane (98.8 g). The mixture was allowed to stir at room temperaturefor 30 minutes. The solution was sparged with nitrogen gas for 15minutes.

The monomer and initiator solution was fed to the reaction flask with aperistaltic pump over 1.2 hours at a rate of 2.1 g/min.

Upon completion of the monomer and initiator feed, a solution of2,2-azobis(2,4-dimethylvaleronitrile (Vazo® 52, 1.24 g, 5.0 mmol) anddioxane (23.6 g) was fed to the reaction flask with a peristaltic pumpover 10 minutes at a rate of 2.5 g/min.

When complete, the reaction mixture was held at 85° C. for 1.5 hours.

After cooling to room temperature, a 70 g portion of the reactionmixture was precipitated into 0.7 L of methanol. The white precipitatewas isolated by vacuum filtration and dried in a vacuum oven overnightat 50° C. The remainder of the reaction mixture was utilized in thepolymer modification experiments described below

EXAMPLES 5 and 6

18.2 g (92%) were obtained as a white powder. GPC (THF) M_(W)=7000 Da,M_(n),=4200 Da, PDI: 1.6.

EXAMPLE 5 Synthesis of ANTMI/ANTMA/HNMA-2/TBA (25.1/25.1/33.7/16.1)Modified Polymer

Into a 0.25 L, 3-necked round bottom flask, fitted with a magnetic stirbar, condenser, heating mantle, and temperature controller andcontaining the remaining reaction mixture from Example 4 (above) wereadded maleimide (MI, 4.09 g, 42.1 mmol). The reaction mixture was heldat 85° C. for 6 hours.

After cooling to room temperature, a 52 g portion of the reactionmixture was diluted with 10 g dioxane and precipitated into 0.7 L ofmethanol. The white precipitate was isolated by vacuum filtration anddried in a vacuum oven overnight at 50° C. to give a polymer in whichpendant anthracene groups are partly derivatized to ANTMI [4+2]Diels-Alder cycloadduct.

The remainder of the reaction mixture was utilized in Example 6 below.

17.2 g (100%) were obtained as a white powder. GPC (THF) M_(W)=8700 Da,M_(n),=5000 Da, PDI: 1.7.

EXAMPLE 6 Synthesis of ANTMI/HNMA-2/TBA 50.2/33.7/16.1 Modified Polymer

Into a 0.25 L, 3-necked round bottom flask, fitted with a magnetic stirbar, condenser, heating mantle, and temperature controller andcontaining the remaining reaction mixture from Example 4 above, wereadded maleimide (MI, 2.50 g, 25.7 mmol). The reaction mixture was heldat 85° C. for 6 hours.

After cooling to room temperature, the reaction mixture precipitatedinto 0.7 L of cmethanol. The white precipitate was isolated by vacuumfiltration and dried in a vacuum oven overnight at 50° C. to give apolymer in which pendant anthracene groups are fully derivatized toANTMI [4+2] Diels-Alder cycloadduct 22.7 g (74%) were obtained as awhite powder. GPC (THF) M_(W)=9000 Da, M_(n),=5100 Da, PDI: 1.8.

EXAMPLES 7-8 Syntheses of Additional ANT-MI Containing Polymers byDirect Polymerization EXAMPLE 7 Synthesis of MI/ANTMA/HNMA-2/TBA34.3/31.5/25.0/9.2 Tetrapolymer

Into a 2.0 L, 5-necked roundbottom flask, fitted with a mechanicalstirrer, condenser, heating mantle, and temperature controller, wereadded 215 g dioxane. The solvent was sparged with nitrogen gas for 15minutes. The solvent was heated to 85° C.

Into a 2.0 L Erlenmeyer flask with stirbar were added maleimide (MI,53.10 g, 547 mmol), 9-anthracene-methyl methacrylate (ANTMA, 138.7 g,502 mmol), 2-hydroxynaphthalene-methylmethacrylate monomer (HNMA-2,96.53 g, 398 mmol), t-butyl acrylate (TBA, 18.80 g, 147 mmol) anddioxane (423.5 g). The mixture was allowed to stir at room temperaturefor 30 minutes. The solution was sparged with nitrogen gas for 15minutes.

Into a 500 mL bottle were added 2,2-azobis(2,4-dimethylvaleronitrile(Vazo® 52, 11.89 g, 48.0 mmol) and dioxane (78.0 g).

The monomer solution was fed to the reaction flask with a peristalticpump over 1.5 hours at a rate of 8.5 g/min. The initiator solution wasalso fed to the reaction flask with a peristaltic pump over this periodat a rate of 1.1 g/min (90 min feed).

Upon completion of the monomer and initiator feed, a solution of2,2-azobis(2,4-dimethylvaleronitrile (Vazo® 52, 7.93 g, 32.0 mmol) anddioxane (151 g) was fed to the reaction flask with a peristaltic pumpover 20 minutes at a rate of 8.2 g/min.

When complete, the reaction mixture was held at 85° C. for 1.5 hours.

After cooling to room temperature, the reaction mixture was precipitatedinto 15.0 L of methanol. The white precipitate was isolated by vacuumfiltration, washed with 3.0 L of methanol and dried in a vacuum ovenovernight at 50° C.

195.1 g (64%) of the title polymer was obtained as a white powder. GPC(THF) M_(W)=9300 Da, M_(n)=6500 Da, PDI: 1.5.

EXAMPLE 8 Synthesis of MI/ANTMA/HNMA-2/TBA 33.2/31.3/26.8/8.7Tetrapolymer

Into a 2.0 L, 5-necked roundbottom flask, fitted with a mechanicalstirrer, condenser, heating mantle, and temperature controller, wereadded 218 g dioxane. The solvent was sparged with nitrogen gas for 15minutes. The solvent was heated to 85° C.

Into a 2.0 L Erlenmeyer flask with stirbar were added maleimide (MI,51.39 g, 529 mmol), 9-anthracene-methyl methacrylate (ANTMA, 137.9 g,499 mmol), 2-hydroxynaphthalene-methylmethacrylate monomer (HNMA-2,103.4 g, 427 mmol), t-butyl acrylate (TBA, 17.82 g, 139 mmol) anddioxane (430 g). The mixture was allowed to stir at room temperature for30 minutes. The solution was sparged with nitrogen gas for 15 minutes.

Into a 500 mL bottle were added 2,2-azobis(2,4-dimethylvaleronitrile(Vazo® 52, 11.89 g, 48.0 mmol) and dioxane (78.0 g).

The monomer solution was fed to the reaction flask with a peristalticpump over 1.5 hours at a rate of 7.5 g/min. The initiator solution wasalso fed to the reaction flask with a peristaltic pump over this periodat a rate of 0.9 g/min (90 min feed).

Upon completion of the monomer and initiator feed, a solution of2,2-azobis(2,4-dimethylvaleronitrile (Vazoe 52, 7.93 g, 32.0 mmol) anddioxane (151 g) was fed to the reaction flask with a peristaltic pumpover 20 minutes at a rate of 8.2 g/min.

When complete, the reaction mixture was held at 85° C. for 1.5 hours.

After cooling to room temperature, the reaction mixture was precipitatedinto 15.0 L of methanol. The white precipitate was isolated by vacuumfiltration, washed with 3.0 L of methanol and dried in a vacuum ovenovernight at 50° C.

186.6 g (60%) of the tile polymer was obtained as a white powder. GPC(THF) M_(w),=9200 Da, M_(n)=6350 Da, PDI: 1.5.

EXAMPLE 9 Coating Composition Preparation and Lithographic Processing

An underlying coating composition is prepared by admixing the followingmaterials:

Resin

Polymer of Example 5 above

Photoacid Generator

triphenyl sulfonium salt

Solvent

ethyl lactate

The resin is present in an amount of 5 grams. The photoacid generatorcompound is present in an amount of about 0.5 weight percent of totalsolids (all components expect solvent).

This formulated coating composition is spin coated onto a siliconmicrochip wafer and is cured at 210° C. for 60 seconds on a vacuumhotplate to provide a dried (but not cross-linked) coating layer.

A commercially available 193 nm positive-acting photoresist is thenspin-coated over the cured coating composition layer. The applied resistlayer is soft-baked at 100° C. for 60 seconds on a vacuum hotplate,exposed to patterned 193 nm radiation through a photomask, post-exposurebaked at 110° C. for 60 seconds and then developed with 0.26 N aqueousalkaline developer where both the photoresist later and underlyingcoating composition are removed in areas defined by the photomask.

EXAMPLE 10 Coating Composition Preparation and Lithographic Processing

An underlying coating composition is prepared by admixing the followingmaterials:

Resin

Polymer of Example 6 above

Photoacid Generator

triphenyl sulfonium salt

Solvent

ethyl lactate

The resin is present in an amount of 5 grams. The photoacid generatorcompound is present in an amount of about 0.5 weight percent of totalsolids (all components expect solvent).

This formulated coating composition is spin coated onto a siliconmicrochip wafer and is cured at 210° C. for 60 seconds on a vacuumhotplate to provide a dried (but not cross-linked) coating layer.

A commercially available 193 nm positive-acting photoresist is thenspin-coated over the cured coating composition layer. The applied resistlayer is soft-baked at 100° C. for 60 seconds on a vacuum hotplate,exposed to patterned 193 nm radiation through a photomask, post-exposurebaked at 110° C. for 60 seconds and then developed with 0.26 N aqueousalkaline developer where both the photoresist later and underlyingcoating composition are removed in areas defined by the photomask.

EXAMPLE 11 Coating Composition Preparation and Lithographic Processing

An underlying coating composition is prepared by admixing the followingmaterials:

Resin

Polymer of Example 7 above

Photoacid Generator

triphenyl sulfonium salt

Solvent

ethyl lactate

The resin is present in an amount of 5 grams. The photoacid generatorcompound is present in an amount of about 0.5 weight percent of totalsolids (all components expect solvent).

This formulated coating composition is spin coated onto a siliconmicrochip wafer and is cured at 210° C. for 60 seconds on a vacuumhotplate to provide a dried (but not cross-linked) coating layer.

A commercially available 193 nm positive-acting photoresist is thenspin-coated over the cured coating composition layer. The applied resistlayer is soft-baked at 100° C. for 60 seconds on a vacuum hotplate,exposed to patterned 193 nm radiation through a photomask, post-exposurebaked at 110° C. for 60 seconds and then developed with 0.26 N aqueousalkaline developer where both the photoresist later and underlyingcoating composition are removed in areas defined by the photomask.

EXAMPLE 12 Coating Composition Preparation and Lithographic Processing

An underlying coating composition is prepared by admixing the followingmaterials:

Resin

Polymer of Example 8 above

Photoacid Generator

triphenyl sulfonium salt

Solvent

ethyl lactate

The resin is present in an amount of 5 grams. The photoacid generatorcompound is present in an amount of about 0.5 weight percent of totalsolids (all components expect solvent).

This formulated coating composition is spin coated onto a siliconmicrochip wafer and is cured at 210° C. for 60 seconds on a vacuumhotplate to provide a dried (but not cross-linked) coating layer.

A commercially available 193 nm positive-acting photoresist is thenspin-coated over the cured coating composition layer. The applied resistlayer is soft-baked at 100° C. for 60 seconds on a vacuum hotplate,exposed to patterned 193 nm radiation through a photomask, post-exposurebaked at 110° C. for 60 seconds and then developed with 0.26 N aqueousalkaline developer where both the photoresist later and underlyingcoating composition are removed in areas defined by the photomask.

EXAMPLE 13 Coating Composition Preparation and Lithographic Processing

An underlying coating composition is prepared by admixing the followingmaterials:

Resin

Polymer Blend from Examples 7 and 8 above

Photoacid Generator

triphenyl sulfonium salt

Solvent

ethyl lactate

The resins are present in equal weight amounts for a combined weight of5 grams. The photoacid generator compound is present in an amount ofabout 0.5 weight percent of total solids (all components expectsolvent).

This formulated coating composition is spin coated onto a siliconmicrochip wafer and is cured at 210° C. for 60 seconds on a vacuumhotplate to provide a dried (but not cross-linked) coating layer.

A commercially available 193 nm positive-acting photoresist is thenspin-coated over the cured coating composition layer. The applied resistlayer is soft-baked at 100° C. for 60 seconds on a vacuum hotplate,exposed to patterned 193 nm radiation through a photomask, post-exposurebaked at 110° C. for 60 seconds and then developed with 0.26 N aqueousalkaline developer where both the photoresist later and underlyingcoating composition are removed in areas defined by the photomask.

EXAMPLE 14 Additional Coating Composition and Lithographic Processing

A coating composition is prepared by admixing the following components:materials:

Resins

Polymer Blend from Examples 7 and 8 above

Photoacid Generator

triphenyl sulfonium salt

Solvent

methyl 2-hydroxyisobutyrate

In this coating composition, the resins are present in equal weightamounts for a combined weight of 3.2 grams and the photoacid generatoris present at about 2% weight percent of total solids (all materialsexcept solvent). The solvent is present in an amount of about 96 weightpercent of the total coating composition weight.

This coating composition is spin coated onto a silicon wafer substrateand baked at 215° C. to remove solvent, but does not result incrosslinking of the coating composition layer.

EXAMPLE 15 Test to Confirm that Thermal Treatment of an UnderlyingCoating Composition Does Not Result in Crosslinking (Molecular WeightIncrease of Composition Components)

A solution of a polymer containing polymerized units of maleimide,polyhydroxystyrene and 9-anthracene-methyl methacrylate were spin castonto 8″ silicon wafers and baked at 180° C. and 240° C. An unbakedcoating of each material was also prepared. Formulations containing thesame polymer but also a photoacid generator compound were also preparedand coatings were made on 8″ silicon wafers at the same baketemperatures (room temperature, 180° C. and 240° C.). After processingas described above, all of the coated films were scraped, readilydissolved in THF and molecular weight measured by GPC.

The weight-average molecular weight data for the polymer films with andwithout PAG showed minimal change after thermal processing thusindicating that crosslinking did not take place upon the thermaltreatments.

EXAMPLE 16 Monomer Synthesis

Scheme 3 below in this Example illustrates he synthesis of apolymerizable methacrylate monomer with a pendant 6-HNA chromophore.This monomer can be prepared in two steps from 6-hydroxy-2-naphthanoicacid.

EXAMPLE 17 Sequential Post-Polymerization Modification of aMulti-Functional Poly(acrylate) to Introduce a Pendant 6-HNA Chromophoreand the Desired DBARC Performance Characteristics

In Scheme 4 immediately below, the sequential modification of amulti-functional poly(acrylate) pre-polymer, polymer 7 is illustrated.

In the following discussion, reference numerals indicate those materialsof the same number as set forth in Scheme 4 above. Upon treatment of theepoxy-function polymer 7 with 6-hydroxy-2-naphthoic acid (6-HNA), in thepresence of a catalyst (benzyl triethyl ammonium chloride), thecarboxylic acid undergoes an epoxy ring opening reaction with thependant glycidyl groups in polymer 7 to afford the modified polymer 8A.The ratio of 6-HNA, polymer 7, the catalyst, and the temperature may bevaried to control the degree of 6-HNA attachment in the polymer. Theoptical properties of the resulting modified polymer, 8A, are modifiedby the attachment of the pendant 6-HNA groups to afford the desiredabsorption (k value) at 248 nm.

Both pre-polymer 7 and 6-HNA modified-polymer 8A present a dienefunctionality, the pendant anthracene group. This anthracene group doesnot react under the conditions presented for the 6-HNA attachmentreaction. In addition, the reagents present in the reaction mixture willnot interfere with any subsequent Diels-Alder reaction between theanthracene group and maleimide. As a result, we regard polymer 7 as amultifunctional material with two pendant and selective functionalgroups (the epoxy and the anthracene). We note that no isolation ofintermediate polymers is necessary, and the entire process can be donein a single reactor.

Upon treatment of polymer 8A with 0.55 equivalents of maleimide (MI,based on anthracene content in pre-polymer 8A) and heating, aDiels-Alder reaction occurs between the pendant anthracene groups andthe maleimide to afford a modified polymer, 8B. The ratio of maleimideto the pendant anthracene groups in polymer 8A, and the reactiontemperature may be varied to control the degree of formation of pendantmaleimide/anthracene cyclo-adducts in the polymer.

Polymer 8B was further reacted with 1.0 equivalents of maleimide (MI,based on anthracene content in pre-polymer 8B) and upon heating, aDiels-Alder reaction occurs between the pendant anthracene groups andthe maleimide to afford a modified polymer, 8C.

An initial evaluation of the optical and physical properties of polymers7, 8A, 8B, and 8C is underway. The results of an initial evaluation ofthese materials is provided in Table 1. From the VASE data, we find thatk value at 248 nm is decreased as the level of maleimide attachment inthe polymer is increased (0.64 for 8A to 0.20 for 8C). From the solventstrip test data, we find that all polymers demonstrate acceptablesolvent strip resistance. For the 8C sample, we find that thedissolution rate in aqueous developer is higher than that of polymers 8Band 8A. Further investigation is warranted and necessary to afford thedesired optical properties and performance characteristics for advancedphotolithographic applications.

TABLE 1 Polymer optical properties and solvent/developer strip testdata. Solvent CD-26 strip strip data data 30 seconds Sample Solvent (Åloss) (Å loss) n/k data 8A Ethyl 0 0 193 nm 1.61/0.195 lactate 248 nm1.522/0.637 8B PGMEA −1@ 210 C. 0 193 nm 1.68/0.38 248 nm 1.70/0.253 8CPGMEA −2@ 210 C. −15 193 nm 1.68/0.410 248 nm 1.74/0.199

EXAMPLE 18

In Scheme 5 immediately below the synthesis of a polymerizablemethacrylast monomer, 2, with a pendant 6-HNA chromophore isillustrated. This monomer can be prepared in three steps from6-hydroxy-2-naphthanoic acid. UV is absorption data is illustrated inScheme 5.

EXAMPLE 19 Synthesis of 6-acetoxy-2-naphthoic Acid

Into a 0.25 L, 3-necked roundbottom flask, fitted with a magneticstirbar and addition funnel were added 6-hydroxy-2-naphthoic acid (20.0g, 106 mmol) and pyridine (100 mL, 1.24 mol). The reaction mixture wascooled to 0° C. in an ice water bath. Acetic anhydride (10.9 g, 106mmol) was added dropwise over 15 minutes. The reaction mixture wasallowed to warm to room temperature and stirred for 18 hours.

The reaction mixture was poured into 1.1 L of a 10:1 mixture of waterand concentrated hydrochloric acid. The white precipitate was isolatedby vacuum filtration and washed with an additional 1 L of water. Thewhite solid was allowed to air dry over 48 hours.

22.5 g (92%) were obtained as a white powder.

¹H NMR (500 MHz, DMSO-d₆): δ3.10 (s, br, 1H), 8.65 (s, 1H), 8.17 (d, 1H,J=10), 8.05 (dd, 2H, J=10, 20), 7.75 (s, 1H), 7.40 (m, 1H), 2.38 (s,311). ¹³C NMR (125 MHz, DMSO-d₆): δ169.5, 167.5, 150.0, 135.5, 131.0,130.5, 130.2, 127.9, 127.8, 126.0, 122.6, 118.6, 21.0.

EXAMPLE 20 Synthesis of 6-acetoxy-2-naphthoic Acid Chloride

Into a 0.25 L, 3-necked roundbottom flask, fitted with a magneticstirbar, addition funnel, and reflux condenser were added6-acetoxy-2-naphthoic acid (30.0 g, 130 mmol), THF (135 mL) anddimethylformamide (approx. 20 drops). Thionyl chloride (18.6 g, 156mmol) was added slowly dropwise to the reaction mixture over 15 minutes.The reaction mixture was heated to reflux for 2.5 hours under nitrogenand allowed to cool to room temperature overnight.

The reaction mixture was evaporated to dryness under reduced pressure atroom temperature. Toluene (50 g) was added and the reaction mixture wasagain evaporated to dryness under reduced pressure at room temperature.Another 50 g portion of toluene was added and the reaction mixture wasagain evaporated to dryness under reduced pressure at room temperature.The off-white solid was triturated with hexanes. The off-white powderwas isolated by vacuum filtration.

31.3 g (96%) were obtained as an off-white powder.

¹1-INMR (500 MHz, CDCl₃): δ8.63 (s, 1H), 7.95 (m, 2H), 7.77 (m, 1H),7.58 (s, 1H), 7.32 (m, 1H), 2.40 (s, 3H). ¹³C NMR (125 MHz, CDCl₃):δ169.2, 168.2, 151.5, 137.0, 134.5, 131.6, 130.2, 130.1, 128.5, 126.0,123.0, 118.8, 21.8.

EXAMPLE 21 Synthesis of 6-Acetoxy-naphthalene-2-carboxylic Acid2-(2-methyl-aciyloyloxy)-ethyl Ester (ANNA-3)

Into an oven-dried 0.25 L, 3-necked roundbottom flask, fitted with amagnetic stirbar and addition funnel under nitrogen were added asolution of hydroxyethylmethacrylate (3.90 g, 30 mmol) and triethylamine(3.40 g, 34 mmol) in THF (40 mL). The reaction mixture was cooled to 0°C. in an ice water bath. A solution of 6-acetoxy-2-naphthoic acidchloride (7.0 g, 28 mmol) in THF (80 mL) was added slowly dropwise tothe reaction mixture over 1.5 hours. The reaction mixture was allowed towarm to room temperature and stirred for 18 hours.

The reaction mixture was poured into water (300 mL) and extracted withethyl acetate (100 mL). The organic extract was washed with water (100mL), 1% sodium bicarbonate solution (2×100 mL) and dried over magnesiumsulfate. The organic extract was evaporated to dryness under reducedpressure at 30° C. An amber oil was obtained that solidified uponstanding. The material is 95% pure by HPLC-MS. The crude material wasused without additional purification.

7.8 g (81%) were obtained as a waxy solid.

¹H NMR (500 MHz, CDCl₃): δ8.62 (s, 1H), 8.04 (m, 2H), 7.89 (m, 1H), 7.64(s, 1H), 7.33 (m, 1H), 6.10 (s, 1H), 5.58 (s, 1H), 4.60 (m, 214), 4.49(m, 211), 2.30 (s, 3H), 1.90 (s, 314). ¹³C NMR (125 MHz, CDCl₃): δ169.4, 167.3, 166.5, 151.3, 137.3, 136.9, 131.5, 131.4, 131.3, 128.6,128.1, 126.6, 125.8, 123.0, 119.2, 63.6, 63.4, 21.0, 18.4.

EXAMPLE 22 Synthesis of MI/ANTMA/HNMA-3/7′BA 30.7/29.0/31.8/8.5Tetrapolymer

Into a 0.25 L, 3-necked roundbottom flask, fitted with a magneticstirbar, condenser, heating mantle, and temperature controller, wereadded 20 g propylene glycol monomethyl ether (PGME). The solvent wassparged with nitrogen gas for 15 minutes. The solvent was heated to 85°C.

Into a 0.5 L Erlenmeyer flask with stirbar were added maleimide (MI,3.73 g, 38 mmol), 9-anthracene-methyl methacrylate (ANTMA, 10.00 g, 36mmol), 6-Acetoxy-naphthalene-2-carboxylic acid2-(2-methyl-acryloyloxy)-ethyl ester (ANMA-3, 13.61 g, 40 mmol), t-butylacrylate (TBA, 1.36 g, 11 mmol) and PGME (30 g). The mixture was allowedto stir at room temperature for 30 minutes. The solution was spargedwith nitrogen gas for 15 minutes. Into a 100 mL bottle were added2,2-azobis(2,4-dimethylvaleronitrile (Vazo® 52, 0.93 g, 4 mmol) and PGME(16 g).

The monomer solution was fed to the reaction flask with a peristalticpump over 1.5 hours at a rate of 0.6 g/min. The initiator solution wasalso fed to the reaction flask with a peristaltic pump over this periodat a rate of 0.2 g/min (90 min feed).

Upon completion of the monomer and initiator feed, a solution of2,2-azobis(2,4-dimethylvaleronitrile (Vazo® 52, 0.62 g, 2 mmol) and PGME(12 g) was fed to the reaction flask with a peristaltic pump over 20minutes at a rate of 0.7 g/min.

When complete, the reaction mixture was held at 85° C. for 1.5 hours.

Acetoxy-de-protection: A solution of ammonium acetate (6.20 g, 80 mmol)and water (3.60 mL, 200 mmol) was added to the reaction mixture. Thereaction was heated at 85° C. for 12 hours.

After cooling to room temperature, the reaction mixture was precipitatedinto 1.0 L of methanol. The white precipitate was isolated by vacuumfiltration, washed with 1.0 L of methanol and dried in a vacuum ovenovernight at 50° C.

20.7 g (77%) were obtained as a white powder.

EXAMPLE 23 Coating Composition Preparation and Lithographic Processing

An underlying coating composition is prepared by admixing the followingmaterials:

Resin

Polymer 8B depicted in Scheme 4 above

Photoacid Generator

triphenyl sulfonium salt

Solvent

ethyl lactate

The resin is present in an amount of 5 grams. The photoacid generatorcompound is present in an amount of about 0.5 weight percent of totalsolids (all components expect solvent).

This formulated coating composition is spin coated onto a siliconmicrochip wafer and is cured at 210° C. for 60 seconds on a vacuumhotplate to provide a dried (but not cross-linked) coating layer.

A commercially available 193 nm positive-acting photoresist is thenspin-coated over the cured coating composition layer. The applied resistlayer is soft-baked at 100° C. for 60 seconds on a vacuum hotplate,exposed to patterned 193 tun radiation through a photomask,post-exposure baked at 110° C. for 60 seconds and then developed with0.26 N aqueous alkaline developer where both the photoresist later andunderlying coating composition are removed in areas defined by thephotomask.

The foregoing description of this invention is merely illustrativethereof, and it is understood that variations and modifications can bemade without departing from the spirit or scope of the invention as setforth in the following claims.

1-30. (canceled)
 31. A coated substrate comprising: (a) a coatingcomposition layer comprising a resin, the resin comprising a reactionproduct of a diene and a dienophile, and wherein the resin comprises ahydroxyl-naphthoic group; and (b) a photoresist layer over the coatingcomposition layer.
 32. A coated substrate comprising: (a) a coatingcomposition layer comprising a component that comprises a component thatcomprises a hydroxyl-naphthoic group; and (b) a photoresist layer overthe coating composition layer
 33. A substrate of claim 1 wherein thecoating composition comprises a resin comprising a 6-hydroxy-2-naphthoicgroup.
 34. A substrate of claim 32 wherein the coating compositioncomprises a resin comprising a 6-hydroxy-2-naphthoic group.
 35. Asubstrate of claim 31 wherein aqueous alkaline development of the layerphotoresist also develops the underlying coating composition layer. 36.A substrate of claim 32 wherein aqueous alkaline development of thelayer photoresist also develops the underlying coating compositionlayer.
 7. The substrate of claim 31 wherein (i) the resin comprising areaction product or (ii) the component that comprises ahydroxyl-naphthoic group is a terpolymer, tetrapolymer or pentapolymer.38. The substrate of claim 31 wherein the coating composition layer isnot crosslinked.
 39. The substrate of 31 wherein the coating compositionlayer is crosslinked.
 40. The substrate of claim 31 wherein the coatingcomposition layer resin comprises a reaction product of animide-containing dienophile and a polycyclic aromatic group.
 41. Thesubstrate of claim 31 wherein the coating composition layer resincomprises a reaction product of (1) a dienophile and (2) an anthraeceneor pentacene group.
 42. An antireflective composition for use with anovercooled photoresist, the antireflective composition comprising: acomponent that comprises a hydroxyl-naphthoic group.
 43. Theantireflective composition of claim 42 wherein the coating compositioncomprises a resin comprising a 6-hydroxy-2-naphthoic group
 44. A methodfor forming a photoresist relief image comprising: (a) applying over asubstrate a coating layer of a composition comprising a component thatcomprises a component that comprises a hydroxyl-naphthoic group; (b)applying a photoresist layer above the coating composition layer.
 45. Amethod of claim 44 wherein the coating composition comprises a resincomprising a 6-hydroxy-2-naphthoic group.
 46. The method of claim 44wherein the applied photoresist layer is exposed to patterned radiationand then developed with an aqueous alkaline developer composition,whereby the developer composition selectively removes in both thephotoresist layer and the underlying coating composition layer the imageas defined in the photoresist layer by patterned radiation.